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Fig. 1: Globular pattern

Fig. 2: Cobblestone pattern

Fig. 3: Reticular pattern

Fig. 4: Unspecific pattern

Fig. 5: Peripheral rim of brown globules indicating naevus enlargement

Dermatologie 16. November 2010

The morphologic universe of melanocytic skin lesions

Even a look with the very eye can uncover many signs of malignity

The term ‘naevus’ includes a wide range of benign melanocytic proliferations that differ in terms of epidemiology, morphology, evolution, and associated melanoma risk [1]. Understanding the morphology and evolution of naevi has improved with the introduction of dermoscopy. This diagnostic tool is a non-invasive, simple, and in-expensive technique for the in vivo observation of surface and sub-surface structures of the skin not visible to the naked eye, such as naevus architecture and superficial vascular plexus. Dermoscopy structures and colours correspond to well-defined histopathologic correlates, thus allowing for clinicians to predict the diagnosis and develop classification systems defining naevus architectural sub-groups without the need for biopsy. In particular, there are 4 main types of dermoscopic patterns have found to be more prevalent in particular age groups and body sites [2].

Globular naevi

Globular naevi, (those present before puberty), characteristically show large globules throughout the lesion that correspond to predominantly dermal nests of melanocytes. In adults these naevi become more elevated with a papillomatous surface and are characterised by a cobblestone pattern. This class of naevi are more prevalent on head, neck and trunk (Fig. 1 and 2).

Reticular naevi

Reticular naevi, (those acquired after puberty), characteristically have a regular pigment network and correspond to small junctional nests of melanocytes or single melanocytes at the basal layer. Naevi of this type are more common on the extremities (Fig. 3).

Homegenous blue naevi

Homogenous blue naevi, (arising before and after puberty), characteristically are structureless and usually persist throughout the patients’ life.

Spitz naevi

Spitz naevi, (seen in children and adults), have multiple streaks of pigmentation or large globules arranged symmetrically at the periphery of the lesion in a radiating pattern like that of a star. Non pigmented lesions of this type (Reed naevi) show reticular depigmentation and dotted vessels. They are most commonly found at the face, limbs, and buttocks [3].

Patterns and colours

Naevi patterns can be described by presentation at body site, for example, acral naevus on palms/soles showing a parallel pigmentary pattern. Naevi can also be described by any special features their pattern presents, such as a halo naevus that has a rim of white scar-like depigmentation surrounding the central pigmented naevus, or by having no characteristic features thus rendering the pattern ‘unspecific’ (Fig. 4).


Naevi can present in a range of colours, with the colour representing the pigment distribution within the anatomical layers. Black and brown indicate the melanin is in keratinocytes or melanocytes found in epidermis or at the dermo-epidermal junction. Grey indicates the melanin is in keratinocytes, melanocytes, or melanophages found in the upper dermis, indicating epidermal and dermal involvement. Blue indicates the melanin is either free or is found in melanocytes or melanophages found in the upper to deep dermis [1]. Research has shown most individuals with multiple naevi have a predominant naevus type that is often related to their skin type [3]. Skin type 1 is associated with light brown lesions with central hypopigmentation, and skin type 4 is associated with dark brown reticular naevi with central hyperpigmentation [6]. This observation in any given patient is a strong indicator the lesion is benign, and the presence of different patterns raises the suspicion of malignancy.

Using dermoscopy to describe naevus evolution and melanoma development

The phenotypic markers associated with melanoma risk are well established and are primarily related to the person’s pigmentary characteristics- such as hair colour, eye colour, and total number of naevi. Currently, key morphological changes involved in the development of melanoma, either from pre-existing naevus or de novo, are not well understood. Studies have shown a peripheral rim of brown globules is a characteristic dermoscopic feature of symmetrically enlarging melanocytic nevi, however in the absence of atypia, enlargement of naevi does not indicate malignancy [5]. Characteristics such as increases in the pigment content of the lesion (black dots, brown globules or network pigmentation), changes in shape, regression, and change in architecture increase a clinician’s suspicion for melanoma. Despite this knowledge, melanomas have been shown to evolve without any of the classical surface microscopic features of melanoma [4] (Fig. 5).


The University of Queensland (U.Q) Dermatology Research Centre lead by Professor Soyer is currently photographing naevi over time with the belief that sequential full body photography and comprehensive dermoscopic naevus capture in high-risk subjects will allow us to fully characterise both the elements and timing of morphological change associated with the life cycle of naevi and, in some instances, their metamorphosis from naevus to melanoma. We are investigating this by recruiting high risk melanoma patients (either personal or first degree family member melanoma history) and matched controls from Queensland. Full-body photography is performed with significant naevi (those of a predetermined size) being marked and dermoscopic images recorded. The participants are then followed up on a 6 monthly basis for five years, where they receive repeat full-body photography and dermoscopic image capture of significant naevi. Naevi are classified in terms of their profile, size, dermoscopic pattern, and colour. This study is being performed in collaboration with Professor Adele Green (QIMR) and Associate Professor Mark Smithers (Melanoma Unit, PAH).

Genetic testing in high risk melanoma patients and matched controls

A number of genes, including MC1R, IRF4, MATP and PLA2G6 are thought to contribute to naevus development. Of these, the strongest genetic effects on melanoma risk are due to variation at the MC1R (melanocortin-1 receptor) locus, a key determinant of hair, eye and skin colour. The correlation between these supposed naevus genes and dermoscopic subtype is unknown.


The aim of the current study is to determine whether there is a correlation between genotype and naevus size, colour, and dermoscopic morphology, and whether this can improve prediction of melanoma risk. This study is being performed in collaboration with Associate Professor Rick Sturm (IMB, UQ) and Dr David Duffy (QIMR), whereby saliva from participants of the above study is collected for genetic analysis.

Together, the combination of individuals’ phenotype, dermoscopic naevus architecture, and associated genotype may provide new avenues for early prediction and diagnosis of melanoma.



1 Zalaudek I, Manzo M, Savarese I, Docimo G, Ferrara G, Argenziano G (2009) The morphologic universe of melanocytic nevi. Semin Cutan Med Surg 28: 149-156

2 Chagchien L, Dusza SW, Chan Agero AL, Korenko AJ, Braun RP, Sachs D, Usman HU, Halpern AC, Marghoob AA (2007) Age- and site-specific variation in the dermoscopic patterns of congenital melanocytic nevi. Arch Dermatol 143: 1007-1014

3 Argenziano G, Zalaudek I, Ferrara G, Hofmann-Wellenhof R, Soyer HP (2007) Proposal of a new classification system for melanocytic naevi. Br J Dermatol 157: 217-227

4 Menzies SW, Guteney A, Avramidis M, Batrac A, McCarthy WH (2001) Short-term digital surface microscopic monitoring of atypical or changing melanocytic lesions. Arch Dermatol 137: 1583-1589

5 Kittler H, Seltenheim M, Dawid M, Pehamberger H, Wolff K, Binder M (2000) Frequency and characteristics of enlarging common melanocytic nevi. Arch Dermatol 136: 316-320

6 Zalaudek I, Argenziano G, Mordente I, et al (2007) Nevus type in dermoscopy is related to skin type in white persons. Arch Dermatol 143: 351-356

The Authors
Dr Nicola C Douglas
Dermatology Research Centre
The University of Queensland
School of Medicine
Princess Alexandra Hospital
Brisbane 4102
Fax: +++61/7/3176 6945

Professor H Peter Soyer
Dermatology Research Centre
The University of Queensland
School of Medicine
Princess Alexandra Hospital
Brisbane 4102
Fax: ++61/7/3176 6945

Nicola C. Douglas and Peter Soyer, Brisbane, Queensland, Australia, Wiener Medizinische Wochenschrift Skriptum 11/2010

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